Field of the Invention
The present invention relates to a process for the preparation of aminoacetic acid esters with a tertiary hydrocarbon radical in the .alpha.-position of formula I: ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are identical or different hydrocarbon radicals, or any two of these radicals forming a carbon ring with the carbon atom on which they are a substituent, and R.sup.4 is an alkyl radical having 1-4 carbon atoms, from the corresponding .alpha.-substituted malonic acid monoamide esters of formula II: ##STR3## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 have the meanings above.
The simplest compounds I are the methyl or ethyl esters of .alpha.-tert-butylaminoacetic acid, which is also called tert-leucine (R.sup.1, R.sup.2 and R.sup.3 methyl, R.sup.4 =methyl or ethyl).